Patterned substrate, electro-optical device, and method for manufacturing an electro-optical device

ABSTRACT

A patterned substrate includes a laminated pattern having laminated patterns that are formed by drying droplets containing a pattern formation material. A lower layer pattern contains lyophilic microparticles that are lyophilic with respect to droplets that form an upper layer pattern.

BACKGROUND

1. Technical Field

The present invention relates to a patterned substrate, anelectro-optical device, and a method for manufacturing anelectro-optical device.

2. Related Art

Known displays equipped with light emitting elements include organicelectroluminescence displays (organic EL displays) used as anelectro-optical device equipped with an organic electroluminescenceelement (organic EL element).

Methods for manufacturing organic EL elements are generally classifiedby the kind of material that makes up its organic EL layer. When thematerial that makes up the organic EL layer is a low-molecular weightorganic material, a vapor phase process is utilized, in which theorganic EL layer is formed by the vapor deposition of this low-molecularweight organic material. On the other hand, when the material that makesup the organic EL layer is a high-molecular weight organic material, aliquid phase process is utilized, in which the high-molecular weightorganic material is dissolved in an organic solvent or the like, and acoating of this solution is applied and dried.

With an inkjet method, which is a type of liquid phase process, tinydroplets of solution are discharged, so the location where the organicEL layer is formed, the film thickness, and the like can be controlledmore precisely than with other liquid phase processes (such as spincoating). Furthermore, since an inkjet method involves discharging thedroplets only in the region where the organic EL layer is to be formed(the element formation region), the high-molecular weight organicmaterial (the raw material) can be used in a smaller amount.

With an inkjet method, however, as the contact angle of the dropletsincreases with respect to the element formation region (that is, aswettability decreases), the discharged droplets end up clumping in justone part of the pattern formation region. As a result, depending on theboundary between droplets and other factors, this can lead to problemssuch as a loss of uniformity of shape (such as the film thicknessuniformity of the organic EL layer, or the film thickness uniformitybetween organic EL layers).

In view of this, it has been proposed in the past that the wettabilityof the discharged droplets be improved in an inkjet method (seeJP-A-2002-334782, for example). In JP-A-2002-334782, the patternformation region (over the transparent electrode) is subjected to alyophilic plasma treatment (oxygen gas plasma treatment) before thedroplets are discharged. This improves the wettability of the dropletsand increases the uniformity of the pattern shape within the patternformation region.

In general, an organic EL layer is formed from a laminated patternhaving at least a light emitting layer that emits colored light and ahole transport layer formed between this light emitting layer and ananode (such as an ITO film). Accordingly, the lower layer pattern (suchas the hole transport layer) has to be subjected to the above-mentionedoxygen plasma treatment or another such surface treatment in order toensure the wettability of the droplets that form the upper layer pattern(light emitting layer).

However, when the lower layer pattern is subjected to an oxygen plasmatreatment or the like, this lower layer pattern is oxidized, which is aproblem in that the electrical characteristics of the pattern areadversely affected. Another problem is that tacking on this plasmatreatment step results in correspondingly lower productivity of theorganic EL display.

SUMMARY

It is an advantage of the invention to provide a patterned substrate, anelectro-optical device, and a method for manufacturing anelectro-optical device, with which the uniformity of a laminated patternformed by drying droplets is increased, and the productivity thereof isimproved.

The patterned substrate according to an aspect of the invention includesa laminated pattern having laminated patterns that are formed by dryingdroplets containing a pattern formation material, wherein the lowerlayer pattern contains lyophilic microparticles that are lyophilic withrespect to the droplets that form the upper layer pattern.

With the patterned substrate of this aspect of the invention, thelyophilic microparticles contained in the lower layer pattern increasethe wettability of the droplets forming the upper layer pattern withrespect to the lower layer pattern. Therefore, an upper layer pattern ofmore uniform shape can be laminated over the lower layer pattern withouthaving to add any surface treatment step or the like. This in turnallows the productivity of the patterned substrate to be increased.

It is preferable that the lyophilic microparticles contain at least oneof silica (SiO₂) particles, titanium oxide (TiO₂) particles, zinc oxide(ZnO) particles, tin oxide (SnO₂) particles, strontium titanate (SrTiO₃)particles, tungsten oxide (WO₃) particles, bismuth oxide (Bi₂O)particles, niobium oxide (NbO or Nb₂O₅) particles, vanadium oxide (VO₂,V₂O₃, or V₂O₅) particles, and iron oxide (Fe₂O₃) particles.Alternatively, they may contain particles each composed of a combinationof at least one of silica (SiO₂), titanium oxide (TiO₂), zinc oxide(ZnO), tin oxide (SnO₂), strontium titanate (SrTiO₃), tungsten oxide(WO₃), bismuth oxide (Bi₂O), niobium oxide (NbO or Nb₂O₅), vanadiumoxide (VO₂, V₂O₃, or V₂O₅), and iron oxide (Fe₂O₃).

With this patterned substrate, because the lower layer pattern containsparticles of at least one of silica (SiO₂), titanium oxide (TiO₂), zincoxide (ZnO), tin oxide (SnO₂), strontium titanate (SrTiO₃), tungstenoxide (WO₃), bismuth oxide (Bi₂O), niobium oxide (NbO or Nb₂O₅),vanadium oxide (VO₂, V₂O₃, or V₂O₅), and iron oxide (Fe₂ 0 ₃), orparticles of a combination of one or more of these, the upper layerpattern can be laminated in a correspondingly more uniform shape, andthe productivity of the patterned substrate can be increased.

It is preferable that the lyophilic microparticles have an averagediameter of 0.5 μm or less.

With this patterned substrate, because the lyophilic microparticles areformed in an average diameter of 0.5 μm or less, the upper layer patterncan be laminated in a correspondingly more uniform shape, and theproductivity of the patterned substrate can be increased.

It is preferable that the pattern formation material be a light emittingelement formation material, and the laminated pattern be a lightemitting element.

With this patterned substrate, the light emitting element can be formedin a more uniform shape, and the productivity of a patterned substrateequipped with this light emitting element can be increased.

The electro-optical device according to another aspect of the inventionincludes an electrode, and a light emitting element having thin filmlayers that are laminated over the electrode and formed by dryingdroplets containing a thin film layer formation material. The lower thinfilm layer contains lyophilic microparticles that are lyophilic withrespect to the droplets that form the upper thin film layer.

With the electro-optical device of this aspect of the invention, thelyophilic microparticles contained in the lower thin film layer increasethe wettability of the droplets that form the upper thin film layer withrespect to the lower thin film layer. Therefore, the upper thin filmlayer having a more uniform shape can be laminated over the lower thinfilm layer without having to add any surface treatment step. This inturn allows the productivity of the electro-optical device to beincreased.

In this electro-optical device, it is preferable that the lyophilicmicroparticles contain at least one of silica (SiO₂) particles, titaniumoxide (TiO₂) particles, zinc oxide (ZnO) particles, tin oxide (SnO₂)particles, strontium titanate (SrTiO₃) particles, tungsten oxide (WO₃)particles, bismuth oxide (Bi₂O) particles, niobium oxide (NbO or Nb₂O₅)particles, vanadium oxide (VO₂, V₂O₃, or V₂O₅) particles, and iron oxide(Fe₂O₃) particles. Alternatively, they contain particles each composedof a combination of at least one of silica (SiO₂), titanium oxide(TiO₂), zinc oxide (ZnO), tin oxide (SnO₂), strontium titanate (SrTiO₃),tungsten oxide (WO₃), bismuth oxide (Bi₂O), niobium oxide (NbO orNb₂O₅), vanadium oxide (VO₂, V₂O₃, or V₂O₅), and iron oxide (Fe₂O₃).

With this electro-optical device, because the lower thin film layercontains particles of at least one of silica (SiO₂), titanium oxide(TiO₂), zinc oxide (ZnO), tin oxide (SnO₂), strontium titanate (SrTiO₃),tungsten oxide (WO₃), bismuth oxide (Bi₂O), niobium oxide (NbO orNb₂O₅), vanadium oxide (VO₂, V₂O₃, or V₂O₅), and iron oxide (Fe₂O₃), orparticles of a combination of one or more of these, the upper thin filmlayer can be laminated in a correspondingly more uniform shape, and theproductivity of the electro-optical device can be increased.

In this electro-optical device, it is preferable that the lyophilicmicroparticles have an average size of 0.5 μm or less.

With this electro-optical device, because the lyophilic microparticlesare formed in an average diameter of 0.5 μm or less, the upper thin filmlayer can be laminated in a correspondingly more uniform shape, and theproductivity of the patterned substrate can be increased.

In this electro-optical device, it is preferable that the light emittingelement be an electroluminescence element having the laminated thin filmlayers between a transparent electrode and a back electrode.

With this electro-optical device, the productivity of an electro-opticaldevice equipped with an electroluminescence element can be increased.

In this electro-optical device, it is preferable that he light emittingelement be an organic electroluminescence element having the thin filmlayers composed of an organic material.

With this electro-optical device, the productivity of an electro-opticaldevice equipped with an organic electroluminescence element can beincreased.

In the method for manufacturing an electro-optical device according tostill another aspect of the invention, thin film layers are formed bydrying droplets containing a thin film layer formation material, andthese thin film layers are laminated to form a light emitting element.The method includes mixing lyophilic microparticles that are lyophilicwith respect to droplets that form an upper thin film layer intodroplets that form a lower thin film layer, and drying the droplets inwhich these lyophilic microparticles have been mixed to form the lowerthin film layer, and then drying the droplets that form the upper thinfilm layer on the lower thin film layer to laminate the upper thin filmlayer over the lower thin film layer.

With the method for manufacturing an electro-optical device of thisaspect of the invention, the lyophilic microparticles mixed into thedroplets that form the lower thin film layer increase the wettability ofthe droplets that form the upper thin film layer with respect to thelower thin film layer. Therefore, an upper thin film layer having a moreuniform shape can be laminated over the lower thin film layer withouthaving to add any surface treatment step. This in turn allows theproductivity of the electro-optical device to be increased.

In this method for manufacturing an electro-optical device, it ispreferable that the lyophilic microparticles contain at least one ofsilica (SiO₂) particles, titanium oxide (TiO₂) particles, zinc oxide(ZnO) particles, tin oxide (SnO₂) particles, strontium titanate (SrTiO₃)particles, tungsten oxide (WO₃) particles, bismuth oxide (Bi₂O)particles, niobium oxide (NbO or Nb₂O₅) particles, vanadium oxide (VO₂,V₂O₃, or V₂O₅) particles, and iron oxide (Fe₂O₃) particles.Alternatively, they contain particles each composed of a combination atleast one of silica (SiO₂), titanium oxide (TiO₂), zinc oxide (ZnO), tinoxide (SnO₂), strontium titanate (SrTiO₃), tungsten oxide (WO₃), bismuthoxide (Bi₂O), niobium oxide (NbO or Nb₂O₅), vanadium oxide (VO₂, V₂O₃,or V₂O₅), and iron oxide (Fe₂O₃).

With this method for manufacturing an electro-optical device, becausethe lower thin film layer contains particles composed of at least one ofsilica (SiO₂), titanium oxide (TiO₂), zinc oxide (ZnO), tin oxide(SnO₂), strontium titanate (SrTiO₃), tungsten oxide (WO₃), bismuth oxide(Bi₂O), niobium oxide (NbO or Nb₂O₅), vanadium oxide (VO₂, V₂O₃, orV₂O₅), and iron oxide (Fe₂O₃), or particles of a combination of one ormore of these, the upper thin film layer can be laminated in acorrespondingly more uniform shape, and the productivity of theelectro-optical device can be increased.

In this method for manufacturing an electro-optical device, it ispreferable that the lyophilic microparticles have an average diameter of0.5 μm or less.

With this method for manufacturing an electro-optical device, becausethe lyophilic microparticles are formed in an average diameter of 0.5 μmor less, the upper thin film layer can be laminated in a correspondinglymore uniform shape, and the productivity of the electro-optical devicecan be increased.

This method for manufacturing an electro-optical device preferablyfurther includes irradiating with light the droplets that form the lowerthin film layer to bring out the lyophilic property of themicroparticles.

With this method for manufacturing an electro-optical device, becausethe lyophilic property of the lyophilic microparticles is brought out byirradiating the droplets that form the lower thin film layer with light,the material of these lyophilic microparticles can be selected from awider range of materials.

In this method for manufacturing an electro-optical device, it ispreferable that the wavelength of the light that irradiates the dropletsthat form the lower thin film layer be 400 nm or less.

With this method for manufacturing an electro-optical device, becausethe lyophilic property of the lyophilic microparticles is brought out byirradiation with light of 400 nm or less, the upper thin film layer canbe laminated in a correspondingly more uniform shape, and theproductivity of the electro-optical device can be increased.

In this method for manufacturing an electro-optical device, it ispreferable that the light emitting element be an electroluminescenceelement having the laminated thin film layers between a transparentelectrode and a back electrode.

With this method for manufacturing an electro-optical device, theproductivity of an electro-optical device equipped with anelectroluminescence element can be increased.

In this method for manufacturing an electro-optical device, it ispreferable that the light emitting element be an electroluminescenceelement having the thin film layers composed of an organic material.

With this method for manufacturing an electro-optical device, theproductivity of an electro-optical device equipped with an organicelectroluminescence element can be increased.

In this method for manufacturing an electro-optical device, it ispreferable that the droplets be discharged from a droplet dischargeapparatus.

With this method for manufacturing an electro-optical device, becausefine droplets are formed by a droplet discharge apparatus, a lightemitting element of more uniform shape can be formed, and theproductivity of an electro-optical device can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified plan view of an organic EL display that is anembodiment of the invention;

FIG. 2 is a simplified plan view of pixels in the same;

FIG. 3 is a simplified cross section of the control element formationregion in the same;

FIG. 4 is a simplified cross section of the control element formationregion in the same;

FIG. 5 is a simplified cross section of the light emitting elementformation region in the same;

FIG. 6 is a flowchart of the steps of manufacturing an electro-opticaldevice in the same;

FIG. 7 is a diagram illustrating the steps of manufacturing anelectro-optical device in the same;

FIG. 8 is a diagram illustrating the steps of manufacturing anelectro-optical device in the same;

FIG. 9 is a diagram illustrating the steps of manufacturing anelectro-optical device in the same;

FIG. 10 is a diagram illustrating the steps of manufacturing anelectro-optical device in the same; and

FIG. 11 is a diagram illustrating the steps of manufacturing anelectro-optical device in the same.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Specific embodiments of the invention will now be described throughreference to FIGS. 1 to 11. FIG. 1 is a simplified plan view of anorganic electroluminescence display (organic EL display) that serves asan electro-optical device.

As shown in FIG. 1, an organic EL display 10 is equipped with atransparent substrate 11 as a patterned substrate. The transparentsubstrate 11 is a non-alkaline glass substrate formed in the shape of asquare, and a square element formation region 12 is formed on thesurface thereof (element formation side 11 a). In this element formationregion 12, a plurality of data lines Ly are formed at a specific spacingand extending in the vertical direction (column direction). The datalines Ly are electrically connected to a data line drive circuit Dr1disposed on the lower side of the transparent substrate 11. The dataline drive circuit Dr1 produces a data signal on the basis of displaydata supplied from an external apparatus (not shown), and outputs thisdata signal at a specific timing to the data lines Ly corresponding tothe data signal.

In the element formation region 12, a plurality of power lines Lvextending in the column direction are provided to the data lines Ly at aspecific spacing. The power lines Lv are electrically connected to acommon power line Lvc formed on the lower side of the element formationregion 12, and drive power produced by a power supply voltage productioncircuit (not shown) is supplied to the power lines Lv.

A plurality of scanning lines Lx extending in the directionperpendicular to the data lines Ly and the power lines Lv (the rowdirection) are formed at a specific spacing in the element formationregion 12. The scanning lines Lx are electrically connected to ascanning line drive circuit Dr2 formed on the left side of thetransparent substrate 11. The scanning line drive circuit Dr2selectively drives specific scanning lines Lx from among the pluralityof scanning lines Lx at a specific timing on the basis of a scanningcontrol signal supplied from a control circuit (not shown), and ascanning signal is outputted to the scanning lines Lx.

A plurality of pixels 13 arranged in a matrix are formed by connectingto the corresponding data lines Ly, power lines Lv, and scanning linesLx where the data lines Ly and the scanning lines Lx intersect. Acontrol element formation region 14 and a light emitting elementformation region 15 are delineated within each of the pixels 13. Thepixels 13 are protected by covering the top side of the elementformation region 12 with a square sealing substrate 16 (the two-dotchain line in FIG. 1).

The pixels 13 in this embodiment are pixels that emit light ofcorresponding colors, and are either red pixels that emit red light, orgreen pixels that emit green light, or blue pixels that emit blue light.These pixels 13 are used to display a full-color image on the back side(display side 11 b) of the transparent substrate 11.

The pixels 13 will now be described. FIG. 2 is a simplified plan view ofthe layout of the control element formation region 14 and the lightemitting element formation region 15. FIGS. 3 and 4 are simplified crosssections of the control element formation region 14 along the one-dotchain lines A-A and B-B, respectively, in FIG. 2. FIG. 5 is a simplifiedcross section of the light emitting element formation region 15 alongthe one-dot chain line C-C in FIG. 2.

First the structure of the control element formation regions 14 will bedescribed. As shown in FIG. 2, a control element formation region 14 isformed on the lower side of each of the pixels 13, and a firsttransistor (switching transistor) T1, a second transistor (drivetransistor) T2, and a holding capacitor Cs are formed in each controlelement formation region 14.

As shown in FIG. 3, the switching transistor T1 is equipped with a firstchannel film B1 at its lowermost layer. The first channel film B1 is ap-type polysilicon film formed in the shape of an island on the elementformation side 11 a, in the middle of which is formed a first channelregion C1. Activated n-type regions (a first source region S1 and afirst drain region D1) are formed flanking the first channel region C1on the left and right sides. In other words, the switching transistor T1is what is known as a polysilicon TFT.

A gate insulation film Gox and a first gate electrode G1 are formed onthe upper side of the first channel region C1, in that order from theelement formation side 11 a. The gate insulation film Gox is a siliconoxide film or other such insulating film having optical transmissivity,and is deposited over substantially the entire surface of the elementformation side 11 a and the upper side of the first channel region C1.The first gate electrode G1 is a tantalum, aluminum, or other suchlow-resistance metal film, formed across from the first channel regionC1, and is electrically connected to a scanning line Lx as shown in FIG.2. As shown in FIG. 3, the first gate electrode G1 is electricallyinsulated by a first interlayer insulation film IL1 deposited on theupper side of the gate insulation film Gox.

When the scanning line drive circuit Dr2 inputs a scanning signalthrough the scanning line Lx to the first gate electrode G1, theswitching transistor T1 is switched on by this scanning signal.

A data line Ly that goes through the first interlayer insulation filmIL1 and the gate insulation film Gox is electrically connected to thefirst source region S1. A first drain electrode Dp1 that goes throughthe first interlayer insulation film IL1 and the gate insulation filmGox is electrically connected to the first drain region D1. As shown inFIG. 3, this data line Ly and first drain electrode Dp1 are electricallyconnected by a second interlayer insulation film IL2 deposited on theupper side of the first interlayer insulation film IL1.

The scanning line drive circuit Dr2 then successively selects thescanning lines Lx one at a time on the basis of line-order scanning,whereupon the switching transistor T1 of the pixel 13 is switched on inits turn and while selected. When the switching transistor T1 isswitched on, the data signal outputted from the data line drive circuitDr1 is outputted through the data line Ly and the switching transistorT1 (channel film B1) to the first drain electrode Dp1.

As shown in FIG. 4, the drive transistor T2 is a polysilicon TFTequipped with a second channel region C2, a second source region S2, anda second drain region D2. A second gate electrode G2 is formed via thegate insulation film Gox on the upper side of a second channel film B2thereof. The second gate electrode G2 is a tantalum, aluminum, or othersuch low-resistance metal film, and as shown in FIG. 2, is electricallyconnected to a lower electrode Cp1 of the holding capacitor Cs and thefirst drain electrode Dp1 of the switching transistor T1. As shown inFIG. 4, the second gate electrode G2 and the lower electrode Cp1 areelectrically connected by the first interlayer insulation film IL1deposited on the upper side of the gate insulation film Gox.

The second source region S2 is electrically connected to an upperelectrode Cp2 of the holding capacitor Cs that goes through the firstinterlayer insulation film IL1. As shown in FIG. 2, this upper electrodeCp2 is electrically connected to the corresponding power line Lv. Inother words, as shown in FIGS. 2 and 4, the holding capacitor Cs, inwhich the first interlayer insulation film IL1 serves as a capacitancefilm, is connected between the second source region S2 and the secondgate electrode G2 of the drive transistor T2. The second drain region D2is electrically connected to a second drain electrode Dp2 that goesthrough the first interlayer insulation film IL1. The second drainelectrode Dp2 and the upper electrode Cp2 are electrically connected bythe second interlayer insulation film IL2 deposited on the upper side ofthe first interlayer insulation film IL1.

When the data signal outputted from the data line drive circuit Dr1 isoutputted through the switching transistor T1 to the first drain regionD1, the holding capacitor Cs stores a charge relative to the outputteddata signal. Then, when the switching transistor T1 is switched off, adrive current relative to the charge stored in the holding capacitor Csis outputted through the drive transistor T2 (channel film B2) to thesecond drain region D2.

Next, the structure of the light emitting element formation regions 15will be described.

As shown in FIG. 2, a square light emitting element formation region 15is formed on the upper side of each of the pixels 13. As shown in FIG.5, an anode 20 is formed as a transparent electrode on the upper side ofthe second interlayer insulation film IL2 in the light emitting elementformation region 15.

The anode 20 is a transparent conductive film having opticaltransmissivity, such as an ITO film, one end of which goes through thesecond interlayer insulation film IL2 and is electrically connected tothe second drain region D2, as shown in FIG. 4. The top side 20 a ofthis anode 20 is made lyophilic to lower layer droplets 25D (see FIG. 9)by a lyophilic treatment (discussed below; step 12 in FIG. 6).

A third interlayer insulation film IL3, such as a silicon oxide filmthat insulates the anode 20 from other anodes 20, is deposited on theupper side of the anode 20. A square through-hole 21 made in theapproximate middle on the upper side of the anode 20 is formed in thisthird interlayer insulation film IL3, and a barrier layer 22 is formedon the upper side of this third interlayer insulation film IL3.

The barrier layer 22 is formed from what is called a positivephotosensitive material, which when exposed to exposure light Lpr (seeFIG. 7) of a specific wavelength, only the exposed portion becomessoluble in a developing solution such as an alkaline solution, and morespecifically is formed from a resin such as a photosensitive polyimidethat repels a lower layer formation solution 25L (see FIG. 9) and anupper layer formation solution 27L (see FIG. 10), which are discussedbelow. A receptacle hole 23 that flares out upward is formed across fromthe through-hole 21. The receptacle hole 23 is formed large enough thatthe lower layer droplet 25D (see FIG. 9) and upper layer droplet 27D(see FIG. 10), which are discussed below, can be accommodated in thecorresponding light emitting element formation region 15. A barrier 24that surrounds the light emitting element formation region 15 (the anode20 and the through-hole 21) is formed by the inner peripheral surface ofthis receptacle hole 23.

A lower thin film layer (hole transport layer) 25 is formed as a lowerlayer pattern on the upper side of the anode 20 within the lightemitting element formation region 15. The hole transport layer 25 is apattern composed of a hole transport layer formation material 25 s (seeFIG. 9) that constitutes a thin film layer formation material and apattern formation material.

The hole transport layer formation material 25 s in this embodiment is,for example, a benzidine derivative, styrylamine derivative,triphenylmethane derivative, triphenylamine derivative, hydrazonederivative, or other such low-molecular weight compound, or ahigh-molecular weight compound whose structure partly includes one ofthese, or polyaniline, polythiophene, polyvinylcarbazole,α-naphthylphenyldiamine, a mixture of poly(3,4-ethylenedioxythiophene)and polystyrenesulfonic acid (PEDOT/PSS) (Baytron P, trademark ofBayer), or another such high-molecular weight compound.

This hole transport layer 25 contains lyophilic microparticles 26 (seeFIGS. 9 and 10). The lyophilic microparticles 26 are composed oftitanium oxide TiO₂) or another substance that is lyophilic with respectto the upper layer droplets 27D discussed below, and are formed in anaverage size of 0.5 μm or less.

An upper thin film layer (light emitting layer) 27 is laminated as anupper layer pattern on the upper side of the hole transport layer 25.The light emitting layer 27 is a pattern composed of the light emittinglayer formation material 27 s (see FIG. 11) that constitutes a thin filmlayer formation material and a pattern formation material.

The light emitting layer 27 in this embodiment is formed from a lightemitting layer formation material 27 s of the corresponding color (a redlight emitting layer formation material that emits red light, a greenlight emitting layer formation material that emits green light, or ablue light emitting layer formation material that emits blue light).Examples of the red light emitting layer formation material include ahigh-molecular weight compound having an alkyl or alkoxy substituent onthe benzene ring of a polyvinylenestyrene derivative, or ahigh-molecular weight compound having a cyano group on the vinylenegroup of a polyvinylenestyrene derivative. Examples of the green lightemitting layer formation material include a polyvinylenestyrenederivative in which an alkyl, alkoxy, or allyl derivative substituenthas been introduced into a benzene ring. Examples of the blue lightemitting layer formation material include a polyfluorene derivative(such as a copolymer of dialkylfluorene and anthracene, or a copolymerof dialkylfluorene and thiophene).

An organic electroluminescence layer (organic EL layer) 30 is formed asa laminated pattern by the hole transport layer 25 and the lightemitting layer 27.

A cathode 31 is formed as a back electrode composed of an opticallyreflective metal film, such as aluminum, on the upper side of thebarrier layer 22 (barrier 24) and the upper side of the organic EL layer30. The cathode 31 is formed so as to cover the entire surface of theelement formation side 11 a, and supplies potential for all of the lightemitting element formation regions 15 shared by the pixels 13.

Specifically, an organic electroluminescence element (organic ELelement) is constituted as a light emitting element by the anode 20, theorganic EL layer 30, and the cathode 31.

When drive current corresponding to the data signal is supplied throughthe second drain region D2 to the anode 20, the organic EL layer 30emits light at a brightness corresponding to this drive current. Here,the light emitted from the organic EL layer 30 toward the cathode 31side (the upper side in FIG. 4) is reflected by the cathode 3 1.Accordingly, almost all of the light emitted from the organic EL layer30 is transmitted through the anode 20, the second interlayer insulationfilm IL2, the first interlayer insulation film IL1, the gate insulationfilm Gox, the element formation side 11 a, and the transparent substrate1, and is emitted outward from the back (the display side 11 b) of thetransparent substrate 11. Specifically, an image based on the datasignal is displayed on the display side 11 b of the organic EL display10.

An adhesive layer 32 composed of an epoxy resin or the like is formed onthe upper side of the cathode 31, and a sealing substrate 16 that coversthe element formation region 12 is applied via this adhesive layer 32.The sealing substrate 16 is a non-alkaline glass substrate, and servesto prevent the oxidation of the pixels 13, the wiring lines Lx, Ly, andLv, and so forth.

Method for Manufacturing Organic EL Display 10

Next, the method for manufacturing the organic EL display 10 will bedescribed. FIG. 6 is a flowchart illustrating the method formanufacturing the organic EL display 10, and FIGS. 7 to 11 are diagramsillustrating this method for manufacturing the organic EL display 10.

As shown in FIG. 6, first an organic EL layer preliminary step (stepS11) is performed, in which the wiring lines Lx, Ly, Lv, and Lvc and thetransistors T1 and T1 are formed on the element formation side 11 a ofthe transparent substrate 11, and the barrier layer 22 is patterned.FIG. 7 is a diagram illustrating this organic EL layer preliminary step.

Specifically, in the organic EL layer preliminary step, first acrystallized polysilicon film is formed by excimer laser or the likeover the entire element formation side 11 a, and this polysilicon filmis patterned to form the channel films B1 and B2. Next, the gateinsulation film Gox composed of a silicon oxide film or the like isformed over the entire upper surface of the element formation side 11 aand the channel films B13 and B2, and a low-resistance metal film oftantalum or the like is deposited over the entire upper surface of thegate insulation film Gox. This low-resistance metal film is patterned toform the gate electrodes G1 and G2, the lower electrode Cp1 of theholding capacitor Cs, and the scanning line Lx.

When the gate electrodes G1 and G2 have been formed, an n-type impurityregion is formed in each of the channel films B1 and B2 by ion doping,using the gate electrodes G1 and G2 as masks. This forms the channelregions C1 and C2, the source regions S1 and S2, and the drain regionsD1 and D2. When the source regions S1 and S2 and the drain regions D1and D2 have been formed in the channel films B1 and B2, respectively,the first interlayer insulation film IL1 composed of a silicon oxidefilm or the like is deposited over the entire upper surface of the gateelectrodes G1 and G2, the scanning line Lx, and the gate insulation filmGox.

When the first interlayer insulation film IL1 has been formed, a pair ofcontact holes is patterned at positions relative to the source regionsS1 and S2 and the drain regions D1 and D2 in the first interlayerinsulation film IL1. Next, a metal film of aluminum or the like isdeposited over the entire upper surface of the first interlayerinsulation film IL1 and in these contact holes, and this metal film ispatterned to form the data line Ly and the upper electrode Cp2 of theholding capacitor Cs corresponding to each of the source regions S1 andS2. At the same time, the drain electrodes Dp1 and Dp2 corresponding tothe drain regions D1 and D2 are formed. The second interlayer insulationfilm IL2 composed of a silicon oxide film or the like is deposited overthe entire upper surface of the data line Ly, the upper electrode Cp2,the drain regions D1 and D2, and the first interlayer insulation filmIL1. This forms the switching transistor T1 and the drive transistor T2.

When the second interlayer insulation film IL2 has been deposited, a viahole is formed at a position across from the second drain region D2 inthis second interlayer insulation film IL2. Then, a transparentconductive film having optical transmissivity, such as an ITO film, isdeposited over the entire upper surface of the second interlayerinsulation film IL2 and in this via hole, and this transparentconductive film is patterned to form the anode 20 that connects to thesecond drain region D2. When the anode 20 has been formed, the thirdinterlayer insulation film IL3 composed of a silicon oxide film or thelike is formed over the entire upper surface of the second interlayerinsulation film IL2 and this anode 20.

When the third interlayer insulation film IL3 has been deposited, asshown in FIG. 7, the entire upper surface of the third interlayerinsulation film IL3 is coated with a photosensitive polyimide resin orthe like to form the barrier layer 22. Developing is then performed byexposing the barrier layer 22 at a position across from the anode 20 toexposure light Lpr of a specific wavelength through a mask Mk, whichresults in the patterning of the receptacle hole 23, whose innerperipheral surface is the barrier 24, in this barrier layer 22.

When the receptacle hole 23 has been patterned, the third interlayerinsulation film IL3 is patterned using the barrier layer 22 as a mask,and a through-hole 21 that communicates with the receptacle hole 23 isformed on the upper side of the anode 20.

This completes the organic EL layer preliminary step in which the wiringlines Lx, Ly, Lv, and Lvc and the transistors T1 and T2 are formed onthe element formation side 11 a, and the receptacle hole 23 ispatterned.

As shown in FIG. 6, when the organic EL layer preliminary step iscomplete (step S11), a surface treatment step, in which the inside ofthe receptacle hole 23 and the surface of the barrier layer 22 aretreated, is performed in order to form the lower layer droplet 25D andthe upper layer droplet 27D discussed below (step S12). FIG. 8 is adiagram illustrating this surface treatment step.

Specifically, in the surface treatment step, first the entire elementformation side 11 a is exposed to an oxygen-based plasma Ps to perform ahydrophilic treatment in which the third interlayer insulation film IL3(through-hole 21) and the anode 20 (top side 20 a) in the receptaclehole 23 are rendered hydrophilic. When this hydrophilic treatment hasbeen performed, the entire element formation side 11 a is exposed to afluorine-based plasma Ps to perform a liquid repellency treatment inwhich the barrier layer 22 (barrier 24) is once again rendered liquidrepellent.

As shown in FIG. 6, when the surface treatment step is complete (stepS12), a lower layer formation step (step S13) is performed, in which alower layer droplet 25D containing the lyophilic microparticles 26 andthe hole transport layer formation material 25 s is formed inside thereceptacle hole 23, and the hole transport layer 25 is formed. FIG. 9 isa diagram illustrating this lower layer formation step.

First, the structure of the droplet discharge apparatus used to form thelower layer droplet 25D will be described.

As shown in FIG. 9, a liquid discharge head 35 that constitutes thedroplet discharge apparatus in this embodiment is equipped with a nozzleplate 36. Numerous nozzles 36 n for discharging a liquid are formedfacing upward on the bottom side (the nozzle formation side 36 a) ofthis nozzle plate 36. A liquid supply chamber 37 that communicates witha liquid reservoir (not shown) and allows a liquid to be supplied to thenozzles 36 n is formed on the upper side of the nozzles 36 n. Adiaphragm 38 that vibrates reciprocally up and down and that expands andcontracts the volume inside the liquid supply chamber 37 is provided onthe upper side of the liquid supply chamber 37. A piezoelectric element39 that vibrates the diaphragm 38 by expanding and contractingvertically is provided on the upper side of each diaphragm 38 at aposition across from the liquid supply chamber 37.

As shown in FIG. 9, a transparent substrate 11 conveyed to the dropletdischarge apparatus is positioned with its element formation side 11 aparallel to the nozzle formation side 36 a and with the center of thereceptacle holes 23 disposed directly under each of the nozzles 36 n.

Here, a lower layer formation liquid 25L produced by dissolving ordispersing the hole transport layer formation material 25 s in a lowerlayer liquid in which the hole transport layer formation material 25 scan be dissolved or dispersed, and mixing the lyophilic microparticles26 into this solution is supplied into the liquid supply chamber 37.

When a drive signal for forming the lower layer droplet 25D is inputtedto the liquid discharge head 35, the piezoelectric element 39 expands orcontracts according to this drive signal, thereby increasing ordecreasing the volume of the liquid supply chamber 37. If the volume ofthe 37 decreases here, the lower layer formation liquid 25L isdischarged as a microscopic lower layer droplet 25 b from the nozzle 36n in an amount corresponding to the reduction in volume. The dischargedmicroscopic lower layer droplet 25 b lands on the top side of the anode20 in the receptacle hole 23. When the volume of the liquid supplychamber 37 then increases, the lower layer formation liquid 25L issupplied from a liquid reservoir (not shown) into the liquid supplychamber 37 in an amount equal to the increase in volume. In other words,the liquid discharge head 35 discharges the required volume of lowerlayer formation liquid 25L toward the receptacle hole 23 by means of theexpansion and contraction of the liquid supply chamber 37. Here, theliquid discharge head 35 discharges the microscopic lower layer droplet25 b in an amount such that the hole transport layer formation material25 s contained in the lower layer droplet 25D will form a film of thedesired thickness.

The microscopic lower layer droplet 25 b discharged into the receptaclehole 23 uniformly wets and spreads out over the entire top side of theanode 20 and inside the through-hole 21 in an amount corresponding tohow much the above-mentioned hydrophilic treatment has been performed.After a while, the uniformly spread-out microscopic lower layer droplets25 b form the lower layer droplet 25D, which has a hemisphericalsurface, by means of the liquid repellency of the barrier 24 and its ownsurface tension, as shown by the two-dot chain line in FIG. 9.

When the lower layer droplet 25D has been formed, the transparentsubstrate 11 (the lower layer droplet 25D) is placed under a specificreduced pressure to evaporate the lower layer liquid of the lower layerdroplet 25D and solidify the hole transport layer formation material 25s in a state in which it uniformly contains the lyophilic microparticles26. The solidified hole transport layer formation material 25 s formsthe hole transport layer 25 in a uniform shape, according to the amountof uniform spreading over the entire top side of the anode 20. Thisforms the hole transport layer 25 containing the lyophilicmicroparticles 26 over the entire top side of the anode 20 in thethrough-hole 21 (receptacle hole 23).

As shown in FIG. 6, when the hole transport layer 25 has been formed(step S13), a lyophilic treatment is performed in which the lyophilicproperty of the lyophilic microparticles 26 is brought out (step S14).Specifically, as shown in FIG. 10, the hole transport layer 25 isirradiated with ultraviolet light Luv with a wavelength of 400 nm orless. The lyophilic microparticles 26 that have been irradiated with theultraviolet light Luv manifest their lyophilic property as a result ofthe production of hydroxyl groups on the surface of the lyophilicmicroparticles 26, the formation of physically adsorbed wateroriginating in these hydroxyl groups, and so forth.

As shown in FIG. 6, when the lyophilic property of the lyophilicmicroparticles 26 has been brought out (step S14), an upper layerformation step (step S15) is performed in which the upper layer droplet27D containing a light emitting layer formation material of thecorresponding color is formed in the receptacle hole 23, and the lightemitting layer 27 is formed. FIG. 11 is a diagram illustrating the upperlayer formation step.

In this upper layer formation step, just as in the lower layer formationstep, a microscopic upper layer droplet 27 b, composed of the upperlayer formation liquid 27L obtained by dissolving or dispersing a lightemitting layer formation material 27 s of one color in an upper layerliquid, is discharged from a nozzle 36 n onto the corresponding holetransport layer 25. The liquid discharge head 35 here discharges themicroscopic upper layer droplet 27 b in an amount corresponding to thedesired film thickness in which the light emitting layer 27 is to beformed in the receptacle hole 23.

The upper layer liquid in this embodiment is a liquid capable ofdissolving or dispersing the light emitting layer formation material 27s, and is a liquid that brings out affinity with the above-mentionedlyophilic microparticles 26.

Its affinity with the lyophilic microparticles 26 contained in the lowerlayer formation liquid 25L causes the microscopic upper layer droplet 27b discharged on the hole transport layer 25 to uniformly wet and spreadout over the entire top side of the hole transport layer 25 in an extentaccording to the amount in which the lyophilic microparticles 26 arecontained. After a while, the microscopic upper layer droplet 27 b thathas uniformly spread out forms the upper layer droplet 27D, which has ahemispherical surface, by means of the liquid repellency of the barrier24 and its own surface tension, as shown by the two-dot chain line inFIG. 9.

When the upper layer droplet 27D has been formed, just as in the lowerlayer formation step described above, the transparent substrate 11(upper layer droplet 27D) is placed under a specific reduced pressure toevaporate the upper layer liquid and solidify the light emitting layerformation material 27 s. The solidified light emitting layer formationmaterial 27 s forms the light emitting layer 27 in a uniform shape (suchas a uniform film thickness distribution within the light emittingelement formation region 15 or a uniform film thickness distributionbetween light emitting element formation regions 15), according to theamount of uniform wetting and spreading over the entire top side of thehole transport layer 25. Specifically, this forms the organic EL layer30 having a uniform shape.

As shown in FIG. 6, when the hole transport layer 25 (organic EL layer30) has been formed (step S15), an organic EL layer post-step (step S16)is performed, in which the cathode 31 is formed over the light emittinglayer 27 (organic EL layer 30) and the barrier layer 22, and the pixel13 is sealed. Specifically, the cathode 31 composed of a metal film suchas aluminum is deposited over the entire top side of the organic ELlayer 30 and the barrier layer 22, forming an organic EL elementcomposed of the anode 20, the organic EL layer 30, and the cathode 31.When the organic EL element has been formed, an adhesive layer 32 isformed by coating the entire top side of the cathode 31 (pixel 13) withan epoxy resin or the like, and the sealing substrate 16 is applied tothe transparent substrate 11 via this adhesive layer 32.

The result of the above is that an organic EL display 10 in which theorganic EL layer 30 has a uniform shape can be manufactured.

Next, the effects of this embodiment, constituted as above, will bedescribed.

With the above embodiment, the lower layer formation liquid 25L wasproduced by mixing the lyophilic microparticles 26 into the lower layerliquid, and the lower layer droplet 25D composed of this lower layerformation liquid 25L was dried to form the hole transport layer 25.Therefore, the upper layer droplet 27D can wet and spread out over theentire top side of the hole transport layer 25 in an extentcorresponding to the amount in which the lyophilic microparticles 26 arecontained. As a result, damage to the hole transport layer 25 by aplasma or other surface treatment can be avoided, and the shape of thelight emitting layer 27 can be made more uniform. This in turn allowsthe shape of the organic EL layer 30 to be made more uniform, andincreases the productivity of the organic EL display 10.

(2) With the above embodiment, the lyophilic microparticles 26 had anaverage size of 0.5 μm or less. Therefore, the shape of the holetransport layer 25 can be made flatter according to how small thelyophilic microparticles 26 are made, and this in turn allows the shapeof the organic EL layer 30 to be made more uniform.

(3) With the above embodiment, the hole transport layer 25 wasirradiated with the ultraviolet light Luv to bring out the lyophilicproperty of the lyophilic microparticles 26. Therefore, just the topside of the hole transport layer 25 can be rendered lyophilic, and thesurface condition (liquid repellency) of the barrier layer 22 and soforth can be maintained better than when the entire surface is treatmentby plasma or the like. As a result, leakage and so forth of thedischarged microscopic upper layer droplet 27 b in the receptacle hole23 can be avoided, and the light emitting layer 27 can be reliablyformed relative to the amount of this microscopic upper layer droplet 27b. This in turn allows the uniformity of shape between organic EL layers30 to be further enhanced.

(4) With the above embodiment, the lower layer droplet 25D was formed bythe microscopic lower layer droplet 25 b discharged from the dropletdischarge apparatus. Therefore, the desired amount of lyophilicmicroparticles 26 can be reliably contained in the lower layer droplet25D (hole transport layer 25), and the organic EL layer 30 can be formedin a more uniform shape than with other liquid phase processes (such asspin coating).

The above embodiment may be modified as follows.

In the above embodiment, the lyophilic microparticles 26 wereconstituted by titanium oxide (TiO₂) particles, but are not limited tothis, and may instead be silica (SiO₂) particles, zinc oxide (ZnO)particles, tin oxide (SnO₂) particles, strontium titanate (SrTiO₃)particles, tungsten oxide (WO₃) particles, bismuth oxide (Bi₂O)particles, niobium oxide (NbO or Nb₂O₅) particles, vanadium oxide (VO₂,V₂O₃, or V₂O₅) particles, iron oxide (Fe₂O₃) particles, or the like.

Alternatively, the lyophilic microparticles 26 may contain particlescomposed of a combination of at least one of silica (SiO₂), titaniumoxide (TiO₂), zinc oxide (ZnO), tin oxide (SnO₂), strontium titanate(SrTiO₃), tungsten oxide (WO₃), bismuth oxide (Bi₂O), niobium oxide (NbOor Nb₂O₅), vanadium oxide (VO₂, V₂O₃, or V₂O₅), and iron oxide (Fe₂O₃).

With the above embodiment, the lyophilic property of the lyophilicmicroparticles 26 was brought out by irradiation with ultraviolet light,but the invention is not limited to this, and the lyophilicmicroparticles 26 can be constituted by lyophilic silica (SiO₂), so thatthe hole transport layer 25 is rendered lyophilic with respect to theupper layer droplet 27D without any irradiation with ultraviolet light.This eliminates the lyophilic treatment step (step S14)² of the holetransport layer 25, and increases the productivity of the organic ELdisplay 10.

With the above embodiment, the hole transport layer 25 of the organic ELdisplay 10 contained the lyophilic microparticles 26, but the inventionis not limited to this, and may be constituted such that the holetransport layer 25 contains the lyophilic microparticles 26 when thelight emitting layer 27 is formed in the course of manufacturing theorganic EL display 10. Specifically, the lyophilic microparticles 26need only exhibit the property of improving wettability when the upperlayer droplet 27D is formed, and need not manifest their lyophilicproperty when the hole transport layer 25 is formed, or after the lightemitting layer 27 has been formed.

With the above embodiment, the laminated pattern was embodied as twolayers, namely, the hole transport layer 25 and the light emitting layer27, but is not limited to this. The laminated pattern may form amultiphoton structure in which these two layers are repeatedlylaminated, or a plurality of thin film layers may be laminated, forexample.

With the above embodiment, the organic EL display 10 was embodied as abottom emission type, but is not limited to this, and may involve a topemission type instead. Alternatively, the light emitting layer 27 may beconstituted as a lower thin film layer, and the lyophilic microparticles26 may be contained in this light emitting layer 27.

With the above embodiment, the hole transport layer formation material25 s and the light emitting layer formation material 27 s were embodiedas high-molecular weight organic materials, but are not limited to this,and conventional low-molecular weight materials may be used instead.

With the above embodiment, the organic EL layer 30 was constituted bythe hole transport layer 25 and the light emitting layer 27, but theconstitution may instead be such that an electron injection layercomposed of laminated films of calcium and lithium fluoride, forexample, is provided to the upper layer of this light emitting layer 27.Also, the electron injection layer here may be formed by droplets, and asurfactant contained in the light emitting layer 27.

With the above embodiment, the control element formation region 14 wasequipped with the switching transistor T1 and the drive transistor T2,but is not limited to this, and the constitution may instead be suchthat a single transistor, or numerous transistors, or numerouscapacitors are used, according to the desired element design.

With the above embodiment, the organic EL layer 30 was formed by aninkjet method, but the invention is not limited to this, and the methodfor forming the organic EL layer 30 may instead be, such that, forexample, the lower layer droplets 25D or the upper layer droplets 27Dare formed by a liquid applied by spin coating or another such method,and the organic EL layer 30 is formed by drying and solidifying thisliquid.

With the above embodiment, the microscopic lower layer droplets 25 bwere discharged by the piezoelectric elements 39, but the invention isnot limited to this, and a resistance heating element may be provided tothe liquid supply chamber 37, for example, and the microscopic lowerlayer droplets 25 b may be discharged by bursting the bubbles formed bythe heating of this resistance heating element.

With the above embodiment, the laminated pattern was embodied as theorganic EL layer 30, but is not limited to this, and may instead becolor filters of various colors formed by discharging droplets on anunderlying layer in which lyophilic microparticles are contained, andmay also be any of various wiring patterns of the scanning lines Lx orthe data lines Ly, for example.

With the above embodiment, the electro-optical device was embodied asthe organic EL display 10, but is not limited to this, and may insteadbe a backlight mounted in a liquid crystal panel, for example, or may bea field effect type of display (FED, SED, etc.) that is equipped with aflat electron emission element, and that utilizes the ability of afluorescent substance to emit light as a result of the electrons emittedfrom this element.

This application claims priority to Japanese Patent Application No.2004-362542. The entire disclosure of Japanese Patent Application No.2004-362542 is hereby incorporated herein by reference.

1. A patterned substrate, comprising a laminated pattern havinglaminated patterns that are formed by drying droplets containing apattern formation material, wherein a lower layer pattern containslyophilic microparticles that are lyophilic with respect to dropletsthat form an upper layer pattern.
 2. The patterned substrate accordingto claim 1, wherein the lyophilic microparticles contain at least one ofsilica particles, titanium oxide particles, zinc oxide particles, tinoxide particles, strontium titanate particles, tungsten oxide particles,bismuth oxide particles, niobium oxide particles, vanadium oxideparticles, and iron oxide particles.
 3. The patterned substrateaccording to claim 1, wherein the lyophilic microparticles containparticles each composed of a combination of at least one of silica,titanium oxide, zinc oxide, tin oxide, strontium titanate, tungstenoxide, bismuth oxide, niobium oxide, vanadium oxide, and iron oxide. 4.The patterned substrate according to claim 1, wherein the lyophilicmicroparticles have an average diameter of 0.5 μm or less.
 5. Thepatterned substrate according to claim 1, wherein the pattern formationmaterial is a light emitting element formation material, and thelaminated pattern is a light emitting element.
 6. An electro-opticaldevice, comprising: an electrode; and a light emitting element havingthin film layers that are laminated over the electrode and formed bydrying droplets containing a thin film layer formation material, whereina lower thin film layer contains lyophilic microparticles that arelyophilic with respect to droplets that form an upper thin film layer.7. The electro-optical device according to claim 6, wherein thelyophilic microparticles contain at least one of silica particles,titanium oxide particles, zinc oxide particles, tin oxide particles,strontium titanate particles, tungsten oxide particles, bismuth oxideparticles, niobium oxide particles, vanadium oxide particles, and ironoxide particles.
 8. The electro-optical device according to claim 6,wherein the lyophilic microparticles contain particles each composed ofa combination of at least one of silica, titanium oxide, zinc oxide, tinoxide, strontium titanate, tungsten oxide, bismuth oxide, niobium oxide,vanadium oxide, and iron oxide.
 9. The electro-optical device accordingto claim 6, wherein the lyophilic microparticles have an averagediameter of 0.5 μm or less.
 10. The electro-optical device according toclaim 6, wherein the light emitting element is an electroluminescenceelement having the laminated thin film layers between a transparentelectrode and a back electrode.
 11. The electro-optical device accordingto claim 10, wherein the light emitting element is an organicelectroluminescence element having the thin film layers composed of anorganic material.